Recently, I have read about Causal Dynamical Triangulation from [here](https://arxiv.org/abs/1109.3879) and [Wikipedia](https://en.wikipedia.org/wiki/Causal_dynamical_triangulation). In Wikipedia it states, > CDT is a modification of quantum Regge calculus where **spacetime is discretized** by approximating it with a piecewise linear manifold in a process called triangulation. I have also read about Loop Quantum Gravity [here](https://arxiv.org/abs/1201.4598) and [Wikipedia](https://en.wikipedia.org/wiki/Loop_quantum_gravity). Again, Wikipedia states that, > The theory gives a **physical picture of spacetime where space and time are granular and discrete directly because of quantization** just like photons in the quantum theory of electromagnetism and the discrete energy levels of atoms. I couldn't find a good explanation of how both are different from each other even though the way they approach to solve the problem of Quantum Gravity looks the same.